Anyone who doesn't see illegal aliens as a problem just has to look at Arizona.

AZCentral

According to a researcher with the Pew Hispanic Center, a third of Arizona's population growth over the past five years has come from illegal immigration.

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According to a Pew report, Arizona now ranks fifth among the states in the number of illegal immigrants, with around 500,000.

But that actually understates the effect of illegal immigration on the state. As a percentage of population, Arizona has the highest concentration of illegal immigrants in the country. Based upon the Pew study, about 9 percent of Arizona's population consists of illegal immigrants.

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The Federation for American Immigration Reform, which wants to sharply curtail immigration and provided most of the funding for Arizona's Proposition 200 last election, has estimated that illegal immigration is costing Arizona $1.3 billion a year.

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As a practical matter, the only way the cost of illegal immigration to Arizona taxpayers is going to be reduced is to reduce the flow of illegal immigration, and that requires federal action.

$1.3 billion a year is a lot for such a small state, but it is nothing compared to the nearly $9 billion illegal aliens cost California.